Changing Land-Atmosphere Feedbacks in Tropical African Wetlands

热带非洲湿地不断变化的土地-大气反馈

• 批准号: NE/I01277X/1
• 负责人: Simon Dadson
• 金额: $ 52.49万
• 依托单位: NERC CEH (Up to 30.11.2019)
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2011
• 资助国家: 英国
• 起止时间: 2011 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FI01277X%2F1
• 关键词: Changing; Land; Atmosphere; Feedbacks; Tropical

The primary aim of the proposed research is to quantify the feedbacks between tropical African wetlands and climate. We will do this by implementing a dynamic wetland inundation scheme in an Earth system model, and test this model against soil moisture, cloud cover and methane (CH4) concentration data obtained through remote Earth observation. Our research will address the following key questions: How does the presence of tropical wetlands affect rainfall at the regional scale? Are wetland emissions of CH4 strongly dependent on seasonal and inter-annual hydrological variability? How will wetland seasonality and associated emissions of CH4 alter under environmental and climate change scenarios? The research proposed here will build on recent developments in land-surface modelling and Earth observation to incorporate detailed hydrological understanding of wetland function into climate models. We will combine novel satellite Earth observations, field measurements, and a new dynamical representation of wetland inundation to add greatly to our understanding of the importance of wetlands in the Earth system under scenarios of environmental change. Wetlands interact with the climate system in two ways. First, they govern the fluxes of heat and water at the land-surface, which can feed back on rainfall at the local and regional scales. Second, wetlands form a key link between the hydrological and carbon cycles, via anoxic degradation of organic matter to release CH4. It is estimated that wetland CH4 emissions represent 20-40% of the global CH4 budget making wetlands the largest single natural source of atmospheric CH4. Both CH4 and hydrological feedbacks are expected to be most active in the tropics, yet it is here that CH4 fluxes are least well quantified. These concerns are amplified in the context of climate change: warming resulting from a doubling of atmospheric CO2 concentrations will likely lead to a 78% increase in wetland emissions of CH4, most of which will come from tropical regions. Moreover, recent rapid increases in global CH4 concentrations have recently been attributed to natural variations in the extent of flooding in tropical wetlands. The lack of robust information on the ways in which tropical wetlands modulate fluxes of heat, water and trace gases to the atmosphere currently hampers progress in predicting the effects of global environmental change. We urgently need a better understanding of how wetlands function in the Earth system.

拟议研究的主要目的是量化非洲热带湿地与气候之间的反馈。我们将通过在地球系统模型中实施动态湿地淹没计划来实现这一点，并将该模型与通过对地观测获得的土壤湿度、云量和甲烷(CH4)浓度数据进行测试。我们的研究将解决以下关键问题：热带湿地的存在如何影响区域尺度的降雨量？湿地甲烷排放量是否强烈依赖于季节和年际水文变化？在环境和气候变化的情况下，湿地的季节性和相关的CH4排放将如何改变？这里提出的研究将以陆面模拟和地球观测的最新发展为基础，将湿地功能的详细水文学理解纳入气候模型。我们将结合新的地球卫星观测、实地测量和湿地淹没的新动态表示，以极大地加深我们对环境变化情景下湿地在地球系统中的重要性的理解。湿地以两种方式与气候系统相互作用。首先，它们控制着地表的热量和水的流动，这可以反馈当地和区域尺度的降雨。其次，湿地通过有机物的缺氧降解释放CH4，形成了水文循环和碳循环之间的关键纽带。据估计，湿地CH4排放量占全球CH4预算的20%-40%，使湿地成为大气CH4的最大自然来源。CH4和水文反馈在热带地区预计都是最活跃的，但正是在这里，CH4通量的量化程度最低。在气候变化的背景下，这些担忧被放大：大气二氧化碳浓度加倍导致的变暖可能会导致湿地甲烷排放量增加78%，其中大部分将来自热带地区。此外，最近全球甲烷浓度的快速上升被归因于热带湿地洪灾程度的自然变化。目前缺乏关于热带湿地调节热通量、水通量和微量气体进入大气的方式的可靠信息，这阻碍了预测全球环境变化影响的进展。我们迫切需要更好地了解湿地在地球系统中的功能。

项目成果

A reduced-complexity model of ?uvial inundation with a sub-grid representation of ?oodplain topography evaluated for England, United Kingdom

针对英国英格兰评估的具有洪泛平原地形子网格表示的简化复杂性河流淹没模型

• DOI: 10.5194/hess-2021-60
• 发表时间: 2021
• 作者: Dadson S

An increase in methane emissions from tropical Africa between 2010 and 2016 inferred from satellite data

根据卫星数据推断 2010 年至 2016 年间热带非洲甲烷排放量增加

• DOI: 10.5194/acp-2019-477
• 发表时间: 2019
• 作者: Lunt M

The 2014 Drought in the Horn of Africa: Attribution of Meteorological Drivers

2014 年非洲之角干旱：气象驱动因素

• DOI: 10.1175/bams-d-15-00115.1
• 发表时间: 2015
• 期刊: Bulletin of the American Meteorological Society
• 影响因子: 8
• 作者: Marthews T

Mesoscale rainfall patterns observed around wetlands in sub-Saharan Africa

撒哈拉以南非洲湿地周围观察到的中尺度降雨模式

• DOI: 10.1002/qj.3311
• 发表时间: 2018
• 期刊: Quarterly Journal of the Royal Meteorological Society
• 影响因子: 8.9
• 作者: Taylor C

Cooperative filling approaches for the Grand Ethiopian Renaissance Dam

埃塞俄比亚复兴大坝的合作填充方法

• DOI: 10.1080/02508060.2016.1177698
• 发表时间: 2016
• 期刊: Water International
• 影响因子: 2.6
• 作者: Wheeler K